Quiz - Structure and Reactivity | Structure and Reactivity

1

Which compound is most acidic?

FCH2CO2H

ClCH2CO2H

BrCH2CO2H

ICH2CO2H

When comparing the acidity of different molecules, it is actually easier to compare the stability of their respective bases ⇒ less stable base = strongest base ⇒ strongest base = weakest acid

The more electronegative an atom, the stronger the inductive attracting effect and the more stable the base
Electronegativity: F > Cl > Br > I

 

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2

Which compound is most basic?

(CH3)3C​​​​​​​-

CH3CHCH​​​​​​​-

(CH3)2CCH​​​​​​​-

CH3CC​​​​​​​-

Lone pairs of electrons are stabilized by the s character of orbital. The % of s character is 25% in sp3 hybridization, 33% in sp2 and 50% in sp. Therefore, increasing basicity correlates with hybridization as follows: sp < sp2 < sp3​​​​​​​

 

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3

Which compound is an ether?

CH3CH2CH2COH

CH3CH2CH2COOH

CH3CH2OCH2CH3

CH3CH2COCH3

CH3CH2CH2COH ⇒ aldehyde;   CH3CH2CH2COOH ⇒ carboxylic acid;   CH3CH2OCH2CH⇒ ether;   CH3CH2COCH3​​​​​​​ ⇒ ketone

5

Which of the following compounds is a Lewis Base?

BH3

H2O

AlCl3

All of the above

A Lewis base is a substance that donates an electron pair: H2O has 2 pairs of electrons on oxygen ⇒ it is a Lewis base
A Lewis acid is a substance that accepts an electron pair: BH3 and AlCl3 are electron-poor species (boron and aluminium need electrons to follow the octet rule) ⇒ BH3 and AlCl3 are Lewis acids

6

Which of the following cannot react as a nucleophile?

CH3OCH3

CH3OH

CH3O+H2

CH3OCH3

CH3O+H2 is an electrophile: electron-poor species that can form a covalent bond by accepting an electron pair from a nucleophile. Indeed the oxygen atom is positively charged and therefore poor in electrons

7

How do you call 2 molcules with the same molecular formula but different bonds?

Constitutional isomers

Stereoisomers

Functional groups

Conformers

Constitutional isomers:

Chemical species with the same molecular formula but that differ in the way the atoms are connected to each other. They are also called structural isomers